Drain flies are small insects, similar to fruit flies. They are almost moth-like in appearance, as their wings and bodies are covered in hair and look almost furry. Usually less than a quarter of an inch in length, they have broad bodies and large black eyes. Feeding on bacteria found in standing water, they are usually found in kitchens and bathrooms, where they can become problematic for home or business owners.
Adult drain flies live for around 20 days, during which they breed and the female lays her eggs. Eggs are laid in areas such as water traps in plumbing fixtures, around built-in sinks and especially around garbage disposals where decaying matter is found usually in a restaurant kitchen, bar, or a residential home. Anywhere from 30 to 100 eggs are laid, which typically hatch after just two days. The larvae are about as long as the adult drain fly is broad. This stage typically lasts around two weeks, after which the larvae will pupate for another one to two days before hatching as an adult drain fly.